Demystifying Digital Files: Understanding the Relationship Between Size and Quality in Photography

In photography, the terms digital file size and digital file quality are frequently confused. This misunderstanding can affect both new and experienced photographers. Grasping the nuances of file size and quality is crucial when creating high quality photographic prints is the final goal for your images.

What is Digital File Size?

Digital file size denotes the amount of data within a file, typically measured in kilobytes (KB), megabytes (MB), or gigabytes (GB). In photography, file size is influenced by several factors including image dimensions, color depth, and the compression method employed during saving.

When you take a photo with a digital camera, the resulting file can vary dramatically. For example, a high-resolution RAW file from a modern DSLR camera can exceed 30 MB. This larger size allows for rich details, but it also requires considerable storage space. In stark contrast, a JPEG file taken at the same resolution may be as small as 2 MB, making it much easier to share online or store.

What is Digital File Quality?

Digital file quality concerns the clarity, sharpness, and overall appeal of an image. Unlike file size, which can be easily quantified, quality is subjective and can vary with each viewer. Factors that impact digital file quality include resolution, color accuracy, dynamic range, and the presence of visual errors like noise or pixelation. Recent studies show that images with higher resolutions can be up to 80% clearer compared to those with lower resolutions when printed at the same size.

Does File Size Affect Quality?

Generally speaking, larger file sizes mean more data and better-quality images, but this rule has its limits. One thing to keep in mind is that a large file size does not always equal a high resolution file. A 2MB compressed file, like JPEG, can be high quality and high resolution compared to a 10MB uncompressed file, like TIFF, which can be low quality and low resolution.

Tiff - 22MB, 1600px x 2400px, 8"x5.3" @ 300ppi

JPEG - 10.1MB, 3456px x 5184px, 17.3"x11.5" @ 300ppi

For example if we compare the file attributes of the two above files we can clearly see that file size alone (22MB TIFF vs. 10.1MB JPEG) does not correspond to the highest resolution files (3456px x 5184px JPEG vs. 1600px x 2400px TIFF). At first glance you may not notice a difference, however if you enlarge the comparative image, you will see a drastic difference in the detail - ie. resolution.

Final Thoughts

In summary, while digital file size and quality are connected, they each represent different aspects of photography. A larger file can indicate higher quality, but this isn't always guaranteed. Always make sure you are exporting or saving your images at the highest possible resolution after editing - we can always make files smaller, but making them larger is not always possible. Ultimately, if we're talking about images being used solely for web use, all of this doesn't matter quite as much however, once we are talking about printing your photos, all of this really matters.